steptoe wrote: ↑Tue Nov 29, 2022 7:34 pm
Ah ok so i fit that on the red and white wire of the solar panel then plug the usb charger in to that , i have a few solar panels you knwo the ones you use to plug in cig lighter socket to to trickle charge battery when car left for weeks or months i had one i took the cig plug off and fitted croc clips to put on my campervan leisure battery when it was in store .
Thank you mate i order one of them and solder it on the solar panel your a star mate
Are these any good mate i know you are good on solar i wnat to harness as much as i can free to charge AA and AAA batteries
https://www.amazon.co.uk/Fanomini-Porta ... 64&sr=8-13
Hi, Steptoe, If I may chip in...
That 12V -> USB adaptor is an awesome bargain especially that it comes with a little box to fit it in. I'll be getting one.
The fold up Solar array you found at £17 is fair enough except that the 70W rating is probably exaggerated. It gives you your 5V USB output.
There's a bit of an issue that pops up with your proposed objective to charge AA and AAA cells. Something to be aware of and work around.
There are many USB powered AA / AAA chargers cheap as chips on eBay. I have one and tested it. And the little Beggar had a dreadful design flaw. In stepping 5V down to 1.3V, it simply used resistors. That meant that 70% of energy delivered at 5V was simply dissipated as heat!!!!
You need something that either does the 5V to 1.3V conversion using an energy efficient 'buck converter', or you want to charge some batteries in series without the need to step voltage down.
You can use an LED rechargeable lamp with built in charge circuits to do the conversion, efficiently. Or, since you can solder, Here's a link to one that I built into a small battery box. Minimal cost and effort. Ebay provides all the bits.
viewtopic.php?t=18062
Wastes very little of the harvested energy. 12V to 20V in from your panel. Built in about 30 minutes with just a craft knife and soldering iron. Does all the voltage and current regulating with no USB stage. You will need the use of a multimeter and screwdriver.